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index b657486b794b16cdb9bc00560cb0b2f4ab2090dc..2e9b90bcfd55af660d3cb576b1c5e3e21427730e 100644 (file)
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
/*
* SysDB - src/include/core/data.h
- * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * Copyright (C) 2012-2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
SDB_TYPE_BINARY,
};
+#define SDB_TYPE_TO_STRING(t) \
+ (((t) == SDB_TYPE_INTEGER) \
+ ? "INTEGER" \
+ : ((t) == SDB_TYPE_DECIMAL) \
+ ? "DECIMAL" \
+ : ((t) == SDB_TYPE_STRING) \
+ ? "STRING" \
+ : ((t) == SDB_TYPE_DATETIME) \
+ ? "DATETIME" \
+ : ((t) == SDB_TYPE_BINARY) \
+ ? "BINARY" \
+ : "UNKNOWN")
+
/*
* sdb_data_t:
* A datum retrieved from an arbitrary data source.
- *
- * The string and binary objects are managed by whoever creates the data
- * object, thus, they must not be freed or modified. If you want to keep them,
- * make sure to make a copy.
*/
typedef struct {
int type;
} binary; /* SDB_TYPE_BINARY */
} data;
} sdb_data_t;
+#define SDB_DATA_INIT { 0, { .integer = 0 } }
+
+/*
+ * sdb_data_copy:
+ * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
+ * Any dynamic data (strings, binary data) is copied to newly allocated
+ * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
+ * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
+ * in 'dst' will be freed.
+ *
+ * Returns:
+ * - 0 on success
+ * - a negative value else
+ */
+int
+sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
+
+/*
+ * sdb_data_free_datum:
+ * Free any dynamic memory referenced by the specified datum. Does not free
+ * the memory allocated by the sdb_data_t object itself. This function must
+ * not be used if any static or stack memory is referenced from the data
+ * object.
+ */
+void
+sdb_data_free_datum(sdb_data_t *datum);
+
+/*
+ * sdb_data_cmp:
+ * Compare two data points. A NULL datum is considered less than any non-NULL
+ * datum. On data-type mismatch, the function always returns a negative value.
+ *
+ * Returns:
+ * - a value less than zero if d1 compares less than d2
+ * - zero if d1 compares equal to d2
+ * - a value greater than zero if d1 compares greater than d2
+ */
+int
+sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
+
+/*
+ * Operators supported by sdb_data_eval_expr.
+ */
+enum {
+ SDB_DATA_ADD = 1, /* addition */
+ SDB_DATA_SUB, /* substraction */
+ SDB_DATA_MUL, /* multiplication */
+ SDB_DATA_DIV, /* division */
+ SDB_DATA_MOD, /* modulo */
+ SDB_DATA_CONCAT, /* string / binary data concatenation */
+};
+
+#define SDB_DATA_OP_TO_STRING(op) \
+ (((op) == SDB_DATA_ADD) \
+ ? "+" \
+ : ((op) == SDB_DATA_SUB) \
+ ? "-" \
+ : ((op) == SDB_DATA_MUL) \
+ ? "*" \
+ : ((op) == SDB_DATA_DIV) \
+ ? "/" \
+ : ((op) == SDB_DATA_MOD) \
+ ? "%" \
+ : ((op) == SDB_DATA_CONCAT) \
+ ? "||" : "UNKNOWN")
+
+/*
+ * sdb_data_expr_eval:
+ * Evaluate a simple arithmetic expression on two data points. The data-type
+ * of d1 and d2 have to be the same. String and binary data only support
+ * concatenation and all other data types only support the other operators.
+ *
+ * Returns:
+ * - 0 on success
+ * - a negative value else
+ */
+int
+sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
+ sdb_data_t *res);
+
+/*
+ * sdb_data_strlen:
+ * Returns a (worst-case) estimate for the number of bytes required to format
+ * the datum as a string. Does not take the terminating null byte into
+ * account.
+ */
+size_t
+sdb_data_strlen(const sdb_data_t *datum);
+
+enum {
+ SDB_UNQUOTED = 0,
+ SDB_SINGLE_QUOTED,
+ SDB_DOUBLE_QUOTED,
+};
+
+/*
+ * sdb_data_format:
+ * Output the specified datum to the specified string using a default format.
+ * The value of 'quoted' determines whether and how non-integer and
+ * non-decimal values are quoted. If the buffer size is less than the return
+ * value of sdb_data_strlen, the datum may be truncated. The buffer will
+ * always be nul-terminated after calling this function.
+ *
+ * Returns:
+ * - the number of characters written to the buffer (excluding the terminated
+ * null byte) or the number of characters which would have been written in
+ * case the output was truncated
+ * - a negative value else
+ */
+int
+sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
+
+/*
+ * sdb_data_parse:
+ * Parse the specified string into a datum using the specified type. The
+ * string value is expected to be a raw value of the specified type. Integer
+ * and decimal numbers may be signed or unsigned octal (base 8, if the first
+ * character of the string is "0"), sedecimal (base 16, if the string includes
+ * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
+ * "NaN" or may use a decimal exponent. Date-time values are expected to be
+ * specified as (floating point) number of seconds since the epoch. For string
+ * and binary data, the input string is passed to the datum. The function does
+ * not allocate new memory for that purpose. Use sdb_data_copy() if you want
+ * to do that.
+ *
+ * Returns:
+ * - 0 on success
+ * - a negative value else
+ */
+int
+sdb_data_parse(char *str, int type, sdb_data_t *data);
#ifdef __cplusplus
} /* extern "C" */